EP0210957A2 - Elément de pompe à deux étages pour une pompe d'injection de carburant avec un régulateur mécanique - Google Patents

Elément de pompe à deux étages pour une pompe d'injection de carburant avec un régulateur mécanique Download PDF

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Publication number
EP0210957A2
EP0210957A2 EP86830153A EP86830153A EP0210957A2 EP 0210957 A2 EP0210957 A2 EP 0210957A2 EP 86830153 A EP86830153 A EP 86830153A EP 86830153 A EP86830153 A EP 86830153A EP 0210957 A2 EP0210957 A2 EP 0210957A2
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EP
European Patent Office
Prior art keywords
piston
section
stage
pumping element
pressure
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP86830153A
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German (de)
English (en)
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EP0210957A3 (fr
Inventor
Mario Brighigna
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Individual
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Individual
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Publication date
Application filed by Individual filed Critical Individual
Publication of EP0210957A2 publication Critical patent/EP0210957A2/fr
Publication of EP0210957A3 publication Critical patent/EP0210957A3/fr
Withdrawn legal-status Critical Current

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    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F02—COMBUSTION ENGINES; HOT-GAS OR COMBUSTION-PRODUCT ENGINE PLANTS
    • F02M—SUPPLYING COMBUSTION ENGINES IN GENERAL WITH COMBUSTIBLE MIXTURES OR CONSTITUENTS THEREOF
    • F02M45/00—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship
    • F02M45/02—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts
    • F02M45/04—Fuel-injection apparatus characterised by having a cyclic delivery of specific time/pressure or time/quantity relationship with each cyclic delivery being separated into two or more parts with a small initial part, e.g. initial part for partial load and initial and main part for full load
    • F02M45/06—Pumps peculiar thereto

Definitions

  • the invention relates to a two-stage pumping element for a fuel injection pump, in which flow rate of the fuel is governed mechanically.
  • the requisite quantity of fuel is injected into a pre-combustion chamber which communicates with the cylinder, before passing into the combustion chamber proper.
  • the requisite amount of fuel is injected into the combustion chamber direct, and at high velocity, a condition necessary in particular where high performance is to be obtained in terms of output. This signifies that ignition is brought about in a shorter interval of time than is the case with indirect injection, since one firing wave only is propagated, and all the fuel is burned at once. In effect, detonation occurs, with the result that the engine is more noisy, and is subjected to greater mechanical stresses than those undergone by an engine in which injection is indirect.
  • Direct injection offers the advantage, however, of providing lower specific fuel consumption than indirect injection.
  • the object of the invention disclosed is that of overcoming the drawbacks mentioned above.
  • Adopting a pumping element as characterized in the appended claims one is provided with a solution to the problem of embodying such an element for a fuel injection pump with mechanical governor in which the facility exists of injecting each discrete quantity of fuel into the combustion chamber gradually, and at the optimum rate for the given combustion system.
  • Such an object is realized by splitting the injection sequence into two stages, in the first of which a small amount of fuel is injected, sufficient to produce combustion of limited violence; the remainder of the overall quantity of fuel is then injected gradually, metered in such a way that any violent propagation of the firing wavefront is avoided, and detonation duly prevented.
  • the first injection stage is produced with a small diameter pumping element the dimensions of which enable ultra-precise metering of a miniscule quantity of fuel.
  • One of the advantages provided by the invention consists essentially in the fact of obtaining low cost and high dependability, typical of mechanical pump equipment, at one and the same time. This is made possible by virtue of the two-stage design of the pumping element, which first injects a fraction of the requisite discrete quantity of fuel to act as a pilot jet, and then injects the remainder following a given interval of time.
  • the function of the pilot jet is that of providing an activating component to promote more gradual combustion of the quantity of fuel required to produce specified output.
  • Another advantage of the invention is that it gives the facility of metering any given proportion between flow required to produce a pilot jet and flow supplying,the remainder of the discrete quantity of fuel.
  • Such a feature is yet easier to incorporate, at no great expense, with the piston of the pumping element split into two sections; in such an embodiment, one has only to modify the combination of the piston's component parts to produce pumping elements having different operating characteristics.
  • a further advantage provided by a pumping element according to the invention stemming from the fact that the piston is split into two sections, is that of an embodiment in which the two sections are absolutely coaxial and require no special machining.
  • the idea is carried easily into effect by virtue of the fact that the two sections are associated in a loose fit, the flat end of the one section being brought into contact with the slightly-domed ball end of the other in such a way that the two adapt readily and fall into coaxial alignment.
  • This loose fit between the two sections of the piston in no way jeopardizes operation of the pumping element, since the greatest effort required of the piston will always be exerted when its two confronted ends are in contact.
  • An inlet chamber 10 is created between the housing 14 and the barrel 15, which is supplied with fuel at a given pressure via a port-25 in the housing 14.
  • the barrel 15 is held in position within the housing by a check valve 18 the outlet of which, hereinafter referred to as the pressure outlet 8, connects with the combustion chamber.
  • the barrel 15, piston 16 and check valve 18 combine to establish a pressure chamber 3 that connects with the pressure outlet 8.
  • the check valve 18 is of the type having a ball 181 (see figs 1 and 4...8), this being biased by a spring 182 into a position which blocks that end of the pressure outlet 8 connecting with the pressure chamber 3. With such an arrangement, a rise in pressure within the chamber 3 beyond the setting of the bias spring 182 will cause fuel occupying the chamber 3 to exhaust via the pressure outlet 8, thence into the combustion chamber (not illustrated).
  • the piston 16 denotes the first stage of the piston 16, which exhibits a peripheral helical groove 12 into which one end of an orifice 9 emerges, the remaining end of the orifice emerging into the pressure chamber 3.
  • the helical groove 12 connects intermittently, when the piston 16 is reciprocated, with orifices that are located in the barrel 15 and connect with the inlet chamber 10.
  • the piston 16 is rotatable about its own axis, and is engaged from beneath by means, denoted 26, for governing flow rate; accordingly, by rotating the piston 16 and its helical groove 12, one alters the length of time per given engine speed for which the groove 12 is connected with the inlet chamber 10, thereby adjusting the rate of flow.
  • the bottom end of the piston 16 will be seen (figs 1 and 4) to extend a given distance beyond the barrel 15 and through a coil spring 27 which is designed to urge the end of the assembly into contact with the drive component 17, generally a cam 171 (one to each piston 16), and with the governor 26 which engages two parallel faces of the one piston 16.
  • the housing 14 incorporates at least one mounting 28 through which a bolt (not shown) may be inserted.
  • the piston 16 has an enlarged intermediate section 2, the second stage of the two stage design, accommodated slidably and in fluid-tight relationship by and with a corresponding section 15a of the barrel 15 with similarly enlarged bore.
  • a chamber is thus formed between the barrel 15 and the first stage 1 of the piston 16, hereinafter referred to as the second pressure chamber 4, for a purpose that will become apparent.
  • the second stage 2 of the piston 16 also exhibits a helical groove 13, which connects with the second pressure chamber 4 by way of a second orifice 11 in the piston.
  • the barrel 15 incorporates at least a first and a third gallery 5 and 6 designed to connect the inlet chamber 10 with the first and the second pressure chamber 3 and 4, respectively, as well-as being provided with at least one gallery 7 interconnecting the two pressure chambers 3 and 4, which emerges into the first pressure chamber 3 at the same height as the first gallery 5.
  • Fig 2 shows a first embodiment of the piston 16, in which one has two sections 19 and 20 associated in a loose fit.
  • the bottom section 19, which in substantial terms represents the second, larger diameter stage 2 of the piston 16, has a flat top end disposed normal to the longitudinal axis of the bottom section 19 itself, and exhibits a catch 21 directed toward the self-same longitudinal axis and positioned at right angles thereto.
  • top section 20 denotes a slot at bottom of the top section 20, positioned to one side, in which the catch 21 of the bottom section 19 is loosely accommodated.
  • the lower end of the top section 20 offered to the bottom section 19 exhibits a ball end of particularly gentle curvature which is designed make contact with the confronting flat end of the bottom section 19.
  • a structure such as this is made feasible by virtue of the fact that the greatest effort required of the piston 16 will always be compression-related -viz, with the top section 20 driven against the bottom section 19; accordingly, any misalignment between the two will be compensated by the ball end of the top section 20.
  • the second embodiment of the piston 16 illustrated in fig 3 likewise incorporates two sections, top 19 and bottom 20, loosely associated.
  • the bottom section 19, of larger diameter exhibits an axial bore 23 of diameter marginally greater than the diameter of the top section 20 inserted therein.
  • the fit between the two is achieved using a pin 24, inserted loosely in a diametral hole offered by the top section 20, and located tightly in corresponding radial holes in the bottom section 19.
  • the bottom end of the top section 20 in this embodiment likewise exhibits a ball end of gentle curvature, whereas the axial bore 23 of the bottom section 19 is stopped, the base of the bore being embodied flat and located at right angles to the longitudinal axis of the bore itself.
  • the piston 16 At the start of the work cycle, the piston 16 will be at its lower limit position (see fig 4); in this state, the galleries 5, 6 and 7 are fully open, and the pressure chambers 3 and 4 are filled with fuel.
  • the first stage 1 of the piston or pilot pressure (see fig 5), which comes about the moment that the piston, urged upwards by the cam 17, blocks the galleries denoted 5 and 7.
  • the first stage 1 of the piston displaces a given volume of fuel from the chamber denoted 3 into the
  • the volume of fuel displaced by the second stage 2 during this phase will vent to the inlet chamber 10 via the third gallery 6.
  • Pilot pressure terminates the instant that the orifice 9 serving the first stage 1 of the piston is connected with the interconnecting gallery 7 (as in fig 6).
  • Fuel under pressure in the first pressure chamber 3 is now vented to the second pressure chamber 4, in which pressure is lower, and from there drains to the inlet chamber 10 by way of the third gallery 6.
  • the piston 16 accomplishes a given travel during which there is no displacement of fuel through the pressure outlet 8.
  • Set formats for variation of flow can be obtained by appropriate alteration of the lead angle, hand, and shape of the helical grooves 12 and 13 of the first and second stages 1 and 2 (see figs 9...12); there are four basic options in the case in point.
  • the first stage 1 has its groove leading, whereas the second stage 2 has its groove following.
  • the interval of time k between pilot pressure and full pressure remains constant; advance flow on pilot injection a increases whilst retard flow remains constant; retard flow on full injection b increases whilst advance flow remains constant.
  • both stages 1 and 2 have groove leading: the interval of time k between pilot pressure and full pressure is shortened; advance flow increases on both injections, retard flow on both remaining constant.
  • the first stage 1 has groove following, whereas the second stage 2 has groove leading: the interval of time k between pilot pressure and full pressure is shortened; retard flow on pilot injection a increases, and advance flow remains constant; advance flow on full injection b increases whilst retard flow remains constant.
  • both stages 1 and 2 have groove following: the interval of time k between pilot pressure and full pressure is shortened; retard flow is increased on both injections, advance flow on both remaining constant.

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  • Engineering & Computer Science (AREA)
  • Chemical & Material Sciences (AREA)
  • Combustion & Propulsion (AREA)
  • Mechanical Engineering (AREA)
  • General Engineering & Computer Science (AREA)
  • Fuel-Injection Apparatus (AREA)
EP86830153A 1985-07-30 1986-06-06 Elément de pompe à deux étages pour une pompe d'injection de carburant avec un régulateur mécanique Withdrawn EP0210957A3 (fr)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
IT351485 1985-07-30
IT03514/85A IT1186600B (it) 1985-07-30 1985-07-30 Pompante a doppio stadio per pompa iniezione combustibile con sistema di regolazione meccanico delle portate

Publications (2)

Publication Number Publication Date
EP0210957A2 true EP0210957A2 (fr) 1987-02-04
EP0210957A3 EP0210957A3 (fr) 1988-11-23

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ID=11108810

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EP86830153A Withdrawn EP0210957A3 (fr) 1985-07-30 1986-06-06 Elément de pompe à deux étages pour une pompe d'injection de carburant avec un régulateur mécanique

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EP (1) EP0210957A3 (fr)
IT (1) IT1186600B (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991010059A1 (fr) * 1990-01-03 1991-07-11 Robert Bosch Gmbh Systeme d'injection de carburant pour moteurs a combustion interne a injection
EP0619423A2 (fr) * 1993-04-09 1994-10-12 Zexel Corporation Système d'injection de carburant

Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE577288C (de) * 1931-07-12 1933-05-29 Augsburg Nuernberg Akt Ges Mas Brennstoffpumpe
DE744785C (de) * 1942-03-03 1944-01-25 Kloeckner Humboldt Deutz Ag Mit Voreinspritzung arbeitende Brennstoffeinspritzpumpe fuer Brennkraftmaschinen
US2612842A (en) * 1946-11-13 1952-10-07 Worthington Corp Fuel injection pump
FR1163034A (fr) * 1955-08-19 1958-09-22 Bosch Gmbh Robert Pompe à injection de carburant pour moteurs diesel ou gaz-diesel
DE1842137U (de) * 1959-03-28 1961-11-23 Maschf Augsburg Nuernberg Ag Brennstoffpumpe mit koaxial angeordneten kolben fuer brennkraftmaschinen.
FR1319117A (fr) * 1962-04-04 1963-02-22 Maschf Augsburg Nuernberg Ag Pompe d'injection de carburant à deux pistons coaxiaux
DE1187857B (de) * 1961-04-28 1965-02-25 Maschf Augsburg Nuernberg Ag Brennstoffeinspritzpumpe fuer Brennkraftmaschinen mit zwei koaxialen Pumpenkolben
DE1189795B (de) * 1961-04-29 1965-03-25 Maschf Augsburg Nuernberg Ag Brennstoffeinspritzpumpe fuer Brennkraftmaschinen mit zwei koaxialen Pumpenkolben
DE1198610B (de) * 1961-09-01 1965-08-12 Linde Eismasch Ag Kraftstoffeinspritzvorrichtung fuer Kolbenbrenn-kraftmaschinen
GB1198159A (en) * 1967-06-22 1970-07-08 Bosch Gmbh Robert Improvements in Fuel Injection Pumps
GB2028421A (en) * 1978-08-26 1980-03-05 Daimler Benz Ag Fuelinjection pump for internal-combustion engines

Patent Citations (11)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE577288C (de) * 1931-07-12 1933-05-29 Augsburg Nuernberg Akt Ges Mas Brennstoffpumpe
DE744785C (de) * 1942-03-03 1944-01-25 Kloeckner Humboldt Deutz Ag Mit Voreinspritzung arbeitende Brennstoffeinspritzpumpe fuer Brennkraftmaschinen
US2612842A (en) * 1946-11-13 1952-10-07 Worthington Corp Fuel injection pump
FR1163034A (fr) * 1955-08-19 1958-09-22 Bosch Gmbh Robert Pompe à injection de carburant pour moteurs diesel ou gaz-diesel
DE1842137U (de) * 1959-03-28 1961-11-23 Maschf Augsburg Nuernberg Ag Brennstoffpumpe mit koaxial angeordneten kolben fuer brennkraftmaschinen.
DE1187857B (de) * 1961-04-28 1965-02-25 Maschf Augsburg Nuernberg Ag Brennstoffeinspritzpumpe fuer Brennkraftmaschinen mit zwei koaxialen Pumpenkolben
DE1189795B (de) * 1961-04-29 1965-03-25 Maschf Augsburg Nuernberg Ag Brennstoffeinspritzpumpe fuer Brennkraftmaschinen mit zwei koaxialen Pumpenkolben
DE1198610B (de) * 1961-09-01 1965-08-12 Linde Eismasch Ag Kraftstoffeinspritzvorrichtung fuer Kolbenbrenn-kraftmaschinen
FR1319117A (fr) * 1962-04-04 1963-02-22 Maschf Augsburg Nuernberg Ag Pompe d'injection de carburant à deux pistons coaxiaux
GB1198159A (en) * 1967-06-22 1970-07-08 Bosch Gmbh Robert Improvements in Fuel Injection Pumps
GB2028421A (en) * 1978-08-26 1980-03-05 Daimler Benz Ag Fuelinjection pump for internal-combustion engines

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
WO1991010059A1 (fr) * 1990-01-03 1991-07-11 Robert Bosch Gmbh Systeme d'injection de carburant pour moteurs a combustion interne a injection
US5178110A (en) * 1990-01-03 1993-01-12 Robert Bosch Gmbh Fuel injection device for internal combustion engines
EP0619423A2 (fr) * 1993-04-09 1994-10-12 Zexel Corporation Système d'injection de carburant
EP0619423A3 (fr) * 1993-04-09 1995-04-26 Zexel Corp Système d'injection de carburant.
US5443047A (en) * 1993-04-09 1995-08-22 Zexel Corporation Fuel injection system

Also Published As

Publication number Publication date
EP0210957A3 (fr) 1988-11-23
IT8503514A0 (it) 1985-07-30
IT1186600B (it) 1987-12-04

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